Beep,
This information is preliminary. I will continue to test and update findings if they contradict what I am about to state. This is great info Ism, thanks!
I find that in heavy iron, low reactivity settings still lights up the high conductors like copper and silver.
I think I'm starting to notice this too--for anything in the 6 inch range and beyond, I like the tones in R2 over R3. I have done the following test in those areas.
I've gone over the same area in reactivity-1,2,and 3. At no time did I find any objects in reactivity-3 that I missed in 1 or 2. On the contrary, I may have passed up a couple targets in reactivity-3 because the signal was almost nonexistent (depth).
I suspect in this park, I would miss deeper/smaller targets in R3. I've heard a half dime came out of this park years ago, so I wouldn't want to miss one of those in R3 if they're still buried deep there...I've never found one and there aren't many in my hunting radius.
Still, in heavy iron I lean toward reactivity-2 for most of my hunting. Not to say it wouldn't be much more pleasant working in reactivity-3, I have just never found an instance where 3 gave me a clearer signal than 2 or 1 in heavily peppered areas.
The pain is in all the falsing on iron that one must continually double check. The only other alternative in reactivity-1 or 2 is to go at a snails pace and that's just something I cannot do for an extended period of time.
That's what I was running into yesterday...going very slow picking out individual signals. This park has been hunted pretty thoroughly, but if I can manage to not go crazy dissecting these signals, I can probably pull a few more keepers out. I only hunted a very small area because I was going so slow...so there's plenty of real estate left to make me go batty
Now if looking for low conductors (like gold) near iron, I would use the higher reactivity in an iron infested area because the iron would certainly over shadow the signal from a nearby low conductor.
I hadn't considered this, thanks!
BTW, nice job in a trashy park.